.polygon_nav_box {
    position: relative;
    top: 200px;
    left: 50%;
    width: 200px;
    height: 200px;
    transform: translateX(-50%);
}
.polygon_nav_box .polygon_nav {
    position: absolute;
    width: 100%;
    height: 100%;
    border-radius: 50%;
    box-shadow: 0px 0px 25px 0px rgb(255, 255, 255);
    background-color: rgb(0, 0, 0);
}    
.polygon_nav_box .polygon_nav div a {
    position: absolute;
    z-index: -1;
    top: 8%; 
    left: 26%;
    width: 0px;
    height: 0px;
    border-style: solid;
    border-color: transparent;
    border-top-width: 180px;
    border-right-width: 49px;
    border-bottom-width: 49px;
    border-left-width: 49px;
    border-top-color: rgba(0, 0, 0, 0.5);
    text-decoration: none;
    transform-origin: 50% 78%;
}
.polygon_nav_box .polygon_nav div a:hover {
    border-top-color: rgba(0, 0, 0, 0.8);
}
.polygon_nav_box .polygon_nav div a span {
    display: block;
    width: 100px;
    font-size: 1rem;
    text-align: center;
    color: rgb(253, 253, 253);
    background-color: transparent;
    transform: translate(-50px, -175px);
}
.polygon_nav_box .spread_btn {
    position: relative;
    top: 50%;
    left: 50%;
    width: 100px;
    height: 100px;
    font-size: 1.2rem;
    color: rgb(255, 255, 255);
    text-align: center;
    line-height: 5.5;
    border-radius: 50%;
    box-shadow: 0px 0px 0px 0px #fff;
    background-color: rgb(59, 59, 59);
    transform: translate(-50%, -50%);
    cursor: pointer;
    transition: color 0.5s ease 0s,
    background-color 0.5s ease 0s,
    box-shadow 0.5s ease 0s;
}
.polygon_nav_box .spread_btn:hover {
    color: rgb(0, 0, 0);
    box-shadow: 0px 0px 25px -5px #fff;
    background-color: rgb(207, 207, 207);
    transition: all 0.5s ease 0s;
}